Combination lock with security mechanism



March 9, 1965 J. RABINOW ,2

COMBINATION LOCK WITH SECURITY MECHANISM Filed Feb. 23, 1962 Fig./ Fig.2

MAG/V5 T l 620 g 19 I 7 34a 32 Fig. 8

INVENTOR Jacob Rab/now ATTORNEYS United States Patent 3,172,283 CUMBINATIGN LUCK WITH SECURITY MECHANISM Jacob Rabinow, 6920 Selkirk Drive, Bethesda, Md. Filed Feb. 23, 1952, Ser. No. 175,079 16 Claims. (Cl. 70-3t31) This invention relates to improvements in permutation locks, commonly referred to as combination locks, and particularly to a system to increase the security of these locks.

It is generally known that combination locks depend on the alignment of a plurality of members in a preselected manner to permit the actuation of a bolt or the equivalent. The members are generally discs, called tumblers, each of which is provided with a notch, called a gate. It is common for these locks to have three tumblers, although more or less could be used. The security of this kind of lock derives from the large number of possible tumbler permutations before all gates are registered to give the correct combination, so that the chance of the gates being aligned by trial and error is so small as to be negligible.

The tumblers of combination locks are usually operated by direct coupling with separate dials or by means of a drive wheel driven from a single dial. In one class of lock an element, called a fence, is provided on a pivoted fence-lever, and extends transversely across the edges of the tumblers. When all of the gates are in alignment the fence can fit into the gates. The fitting of the fence into the gates allows a bolt to be actuated.

Ordinarily, the fence of a combination lock is held slightly spaced from the peripheries of the tumblers. This is true whether the fence is attached to or mounted on a lever (shown herein) or mounted directly on the bolt (not shown) which is another construction for conventional combination locks. However, it is almost impossible to mass produce all the parts of a combination lock, including the tumblers, to such close tolerances that there will be the same slight difierence in spacing between the outer edges of the tumblers and the fence. Accordingly, by careful manipulation of the drive wheel or dials to cause the fence to assume a position that it contacts the highest tumbler, a skilled person can detect by touch or by very minute sounds or clicks when one of the gates is aligned with the fence. Then by continuing to manipulate the dial, the location of the gate of the next highest tumbler can be detected and aligned with the gate of the first tumbler, and so on until the correct combination is found and the security of the lock is broken. Because of these difficulties, the security of ordinary combination locks is questionable.

There have been attempts to correct the above problem for a number of years. For instance, the Sperduti Patent No. 1,913,859 of June 1933 speaks of attempts to eliminate telltale sounds and vibrations as a developed art, and describes an improvement requiring a particular sequence of longitudinal and angular movement of a shaft of the lock to overcome this problem. The Quintero Patent No. 2,679,743 attacks the same problem by locking the tumbler driver or the tumblers themselves during the first portion of movement of the bolt to assure that the tumblers cannot be vibrated or walked when the fence is brought in contact with the tumbler peripheries. My present invention provides a new approach and solution to the security problem of combination locks.

The principle of my invention is to retain the fence completely clear of the peripheries of the tumblers, the clearance being large so that there is no question but that the fence will be always spaced from the peripheries of the tumblers when the fence is in the rest position. And, I have no means to directly move the fence toward the tumblers. Instead, my fence-moving means move the fence lever in a direction to further separate the fence from the tumbler edges and then release the fence lever and allow it to rebound (and/ or move by spring-action) toward the gates, after decoupling. If the gates are aligned at that moment the fence enters the gates and remains. But if the gates are not aligned, the fence simply taps the edges of the tumblers and returns to the rest position. Thus, the fence samples the position of the tumblers very quickly during which the fence movement is beyond the control of the user of the lock. There is no way for the user to bring the fence in contact with the edges of the tumblers and hold it there while walking the tumblers. Accordingly, it is not possible for a person to break the security of the lock by touch or telltale sounds created by the fence engaging the peripheries of the tumblers and walking the tumblers in the manner described above.

An object of my invention is to provide a new and comparatively simple means to improve the security of combination locks.

Another object of my invention is to improve the security of combination locks by making it impossible for a person to positively move the fence towards the tumblers. Instead, the positive motion of the fence under the control of the user is only when the fence is not contacting the tumblers, and the fence-to-gate coupling is obtained by inertia forces acting on the fence.

Another object of the invention is to provide a combination lock with a unique fence action where the fence samples the position of the gates, and if they are not aligned the fence automatically returns to a rest position spaced from the tumblers regardless of the desires or intentions of the user.

The illustrated forms of my invention are so designed that the fence movement is first away from the tumblers and then toward the tumblers. When the fence moves toward the tumblers, the fence is beyond the control of the user of the lock. I can achieve the same result by a mechanism which ejects or throws the fence toward the tumblers to sample their positions.

Other objects and features of importance will become apparent in following the description of the illustrated forms of the invention, it being understood that these are given by way of example only.

FIGURE 1 is an elevational View of a par-t of a door equipped with one of my locks.

FIGURE 2 is an enlarged partially diagrammatic sectional view taken on line 22 of FIGURE 1.

FIGURE 3 is a perspective view diagrammatically showing another form of my invention.

FIGURE 4 is an enlarged sectional view taken on line 44 of FIGURE 2.

FIGURE 4a is a diagrammatic view showing another modification.

FIGURES 5-5b are diagrammatic views showing the difierent positions of my fence lever when it is being operated.

FIGURES 6-612 show the operation of my fence driver of FIGURE 3.

FIGURE 7 is a fragmentary view showing a conventional fence-return device.

FIGURE 8 is an end elevational view of the embodiment of FIGURE 3.

In the accompanying drawing I have shown a part of a door 10 which diagrammatically represents the door of any cabinet, safe, vault, etc., where a combination lock may be used. Lock 12 has a case 14 whose front cover has a conventional dial 16 (of a plurality of dials not shown), e.g. like the dials shown in Patent No. 2,679,- 743. Since dial 16 actuates tumblers 13, 20, etc. (FIG- URE 3), and the tumblers, their shaft 24 (or shafts) and the dial (or dials) are conventional, the details thereof are omitted. Bolt 26 (FIGURE 1) is shown projected partially from the lock case 14, and knob 28 is on the exterior of the case to actuate the bolt. The final part on the exterior of the case 14 is a knob 32 which is manually turned to actuate fence lever 34 (FIGURE 2) or fence lever 34:: (FIGURE 3). Thus, the knob 32 is attached to shaft 36 (FIGURE 2) or shaft 36a in the embodiment of FIGURE 3.

FIGURE 2 shows the arrangement of parts of my lock. Fence lever 34 is mounted on a fulcrum-defining support 42 between the ends of the lever, and the fence 38 is so positioned that it is capable of projecting into the tumbler gates 40. Support 42 is a stationary vertical member (FIGURE 4) having a pair of spaced cars 44 which cooperate with support wall 46 to form a saddle for the lever 34. To restrict the axial movement of fence lever 34, there is a pair of lateral recesses 48 in lever 34 within which cars 44 nest as shown in FIGURES 2 and 4. Spring 50 is attached to fence lever 34 and to the lower part of the support to establish a rest position (FIGURE 5) for the fence lever and also to return the fence lever to this position (when moved) as will be described later. Other equivalent hinge arrangements, such as a double-acting, spring returned hinge like those used on swinging doors, could be used.

The driver (magnet 62) for fence lever 34 shown in FIGURE 2, ditfers from that shown in FIGURE 3 (cam 62a). However, the action and motion of fence levers 34 and 34a are the same. The rest position of the lever 34 is shown in FIGURE '5. It is manually driven to the position shown in FIGURE 5a at which the lever 34 strikes stationary pin 52 secured to the case 14. In reaching this position the lever rocks about the left edge of the fulcrum wall 46 and stretches spring 50. The next thing that happens is that the driver becomes uncoupled from'lever 34 and the lever springs away from the stop 52. The return force is provided by spring 50 moving lever 34'through the position in FIGURE 5 and to the position shown in FIGURE 5b. If the gates 48 are aligned, the fence 38 will enter the gates. If the gates 40 are not aligned, the lower surface of fence 38 will tap the edge of the tumbler or tumblers which are not in the correct position, and the fence lever will'return by the force of spring 50, to the position shown in FIGURE 5.

Bolt 26 can be actuated only when fence 38 is engaged with the gates, i.e. when the correct combination has been dialed. Again, this is'the usual combination lock procedure and may be accomplished as in Patent .No. 2,679,743 or in other ways for example, as I have shown in FIGURE 1. In this view, pinion is secured to shaft 29, to which knob 28 is attached (FIGURE 1). Pinion 30 is engaged with a rack 31 constrained by guide 33 to slide back and forth when knob '28 is turned. Lever 35 is pivoted to rack 31, and its lower end is coupled to bolt 26 (by fitting in notch 37) which is constrained to horizontal motion by a suitable guide (not shown). The upper end of lever 35 is located between a stop 39 and fence 38 when the fence is engaged with gates 49 (FIGURE 5b). Thus, when lever is swung in one direction (to retract bolt 26) the upper end of thefllever is interposed by fence 38 and the lower end of the lever slides bolt 26 inwardly. of the lock after first uncoupling it from detent 41 or the equivalent. To extend the bolt, lever 35 is swung in the opposite direction during which stop 39 provides the reaction for lever-motion. When lever 35 is moved in a direction to retract bolt and the fence is not in gates 40 (correct combination not dialed), the .fence 38 will be above the upper end of lever 35 (FIGURES 5 and 5a) and there will be nothing to provide a reaction allowing the lever to slide bolt 26.

The driver of FIGURE 2 consists of an eccentric 56, crank (not shown) or the equivalent, attached to shaft 36 and to a link 58. The link 58 is constrained by guide 60 attached to case 14, and has a permanent magnet 62 at its outer end. The stroke of the eccentric and link 58 is so proportioned that when the lever 34 is pulled down against stop 52 the magnet 62 becomes decoupled from the lever 34. When the lever is in the position shown in FIGURE 5, the magnet 62 is approximately at the top of its stroke. Thus, the magnet 62 cannot be used directly to move the lever to the position of F1"- URE 5b. A weaker magnet 64 is attached to case 14 and located beneath the lever 34 adjacent to fence 38. The purpose of "magnet 64 is to hold lever 34 when, and only when, fence 38 engages the gates. The fence 38 can be removed from the gates in any of the usual ways already known and used, such as by a separate disc 17 coupled to shaft .24 (FIGURE 7) and having a suitable ramp 19 to elevate the fence. Patent No. 2,430,711 apparently shows such a disc, but in any case there are many combination locks in common use which rely on a disc having a ramp for this purpose.

The embodiment of FIGURE 3 shows that my driver need not be magnetic. In place of magnet 62, reentrant cam 62a is attached to shaft 36a and cooperates with pin 63 secured to lever 34a. The cam positions of FIG- URES 66b correspond to the fence lever positions of FIGURES 5-5b. The operation starts With FIGURE 6 showing the cam decoupled from pin 63. When the cam is rotated clockwise, pin 63 is captured by the cam and is pulled down (FIGURE 6a) thereby pulling the lever 34a in a direction that the fence 38a assumes the position shown in FIGURE 5a. Then, further rotation of cam 62a releases pin 63 (FIGURE 6b) allowing the action of spring 50 to rock lever 34 so that it successively assumes the positions shown in FIGURES 5 and 5b to engage fence 38a with the tumbler gates. The end 6211 of cam 62a (FIGURE 6) is just long enough to capture pin 63 when the cam is rotated clockwise and when lever 34:: is in the rest position of FIGURE 5, but not if lever 34a is in the operate position of FIGURE 5b. If a user of the lock rotates the cam counterclockwise with the arm 34:: in that position (FIGURE 5b) the tail 62b of the cam will simply strike pin 63 and it will act as a stop-for the cam. Alternatively (FIGURE 8), counterclockwise motionof shaft 36a can be prevented by a one-way clutch 70 operatively connected with shaft 36a.

Summarizing, when it is desired to operate the combination lock, the tumblers are turned in the usual way 'by using dial 16. Then knob 32 is rotated causing the lever to move from the rest position shown in FIGURE 5 to the position shown in FIGURE 5a, then again through the position shown in FIGURE 5 to the position shown in FIGURE 5b. Thereafter, handle or knob 28 is turned to move the bolt 26 in such direction as to complete the actuation of the lock.

If one or more of the tumblers are not in the correct position whenthe driver is operated manually by knob 32, the fence wil strike theedge of the improperly positioned tumbler and will return to its rest position under the action of the spring 50.

It is understood that various changes and modifications may be made without departing from the invention. For example, the centering spring 50 can be replaced by a magnet 50a (FIGURE 40) located just under the center line of the hinge platform 46. My improvement is shown as a part of one common type of combination lock, it being understood that my improvement may function equally well with various designs of permutation locks. Accordingly, all variations, modifications, and the like falling within the scope of the following claims may be resorted to.

I claim:

1. In a combination lock having tumblers provided with gates, and a fence to engage said gates, the improvement comprising a fence lever, means mounting said lever in a normal rest position at which said fence is spaced from said tumblers, said mounting means supporting said lever for movement in such direction that said fence can move away from and toward said gates, manual means including a one-way driver for moving said fence lever in a direction that said fence is separated farther from said tumblers at which said manual means become uncoupled from said fence lever, and means isolated from said manual means and effective upon said uncoupling for returning said fence lever through said rest position and to a position at which said fence engages said gates provided that said gates are in alignment with said fence.

2. A combination lock comprising a tumbler assembly provided with means to turn the tumblers thereof, and a fence lever having a fence to engage the gates of the tumblers when the tumblers are in predetermined rel-a- .tive position, means to retain said lever in a normal position at which said fence is spaced from the edges of said tumblers, and means for rocking said lever in a direction to first space said fence farther from said tumblers and then move said lever toward said tumblers for said fence to engage said gates.

3. In a combination lock having tumblers, means to turn the tumblers, a fence lever, and a fence adapted to engage the gates of said tumblers, the security improvement comprising means including a fulcrum to normally retain said lever in a position that the fence is apprecia'bly spaced from said tumblers, and means to move said lever about said fulcrum to bring said fence into engagement with said gates, said lever moving means releasing said lever during a part of the movement of said fence lever so that the fence lever is decoupled from said moving means prior to the time that said fence makes contact with said tumblers.

4. The combination lock of claim 3 wherein said lever moving means first lifts the fence end of said lever and then releases said lever after which the fence end of said lever moves toward said tumblers.

5. The lock of claim 3 wherein said fulcrum includes a first part about which the lever first rocks, and a second part about which said lever rocks after the lever is released.

6. In a permutation lock provided with movable tumblers having gates, a fence to engage said gates, a sup port, movable means engaging said support for retaining said fence in a rest position normally separated from said tumblers and for returning said fence toward said rest position when moved therefrom, and manual means to oscillate said movable means to bring said fence into engagement with said gates, said manual means disconnecting from said movable means during a portion of each movement of said movable means prior to engage ment of said fence with said gates.

7. In a combination lock which relies on a fence fitting in aligned gates for operation of the lock, the improvement comprising means normally holding the fence spaced from the gates with ample clearance to allow the gates to be moved without contacting the fence, means to further move said fence away from said gates and to then release said fence, and means effective upon said release and separate from the control of said further moving means to move said fence into engagement with said gates.

8. The subject matter of claim 7 wherein said fence holding means include a fence lever and a fulcrum engaged by said fence lever, and said fulcrum having spaced fulcrum portions about which said lever rocks.

9. In a combination lock having tumblers provided with gates and means to operate said tumblers, a fence lever provided with a fence to engage said gates and allow the combination lock to be fully actuated, a support having means to constrain the movement of said lever to rocking motion, resilient means reacting on said lever to establish a rest position for said lever at which said fence is spaced from the peripheries of said tum- 6 blers, means engageable with said lever to rock said lever against the yielding opposition of said resilient means and in a direction to farther separate said fence from said tumbler peripheries in which position said lever rocking means become effectively uncoupled from said lever and at least the stored energy in said resilient means rocks said lever in an opposite direction to bring said fence into engagement with said gates provided that said gates are in alignment, and means to temporarily retain said lever in the position at which said fence engages said gates until said lock is completely operated after which said lever is movable again to said rest position.

10. In a combination lock having tumblers provided with gates, and a fence to engage said gates, the improvement comprising a fence lever to which said fence is fixed, means mounting said lever in a normal rest position at which said fence is spaced from said tumblers, said mounting means mounting said lever for movement in a manner that said fence moves away from and toward said tumblers, manual means for moving said lever in a direction such that said fence is moved from its rest position farther away from said tumblers at which said manual means become effectively uncoupled from said fence lever, yielding means reacting on said fence lever to yieldingly retain said lever in said rest position and to return said lever from said farther position through said rest position and said lever then continuing to move through said rest position in a direction such that said fence contacts said tumblers and engages said gates if the gates are then aligned with said fence.

11. In a combination lock having tumblers provided with gates and means to operate said tumblers, a fence lever provided with a fence to engage said gates and allow the combination lock to be fully actuated, a support having means to constrain the movement of said lever to rocking motion, retaining means reacting 'on said lever to establish a rest position for said lever at which said fence is spaced from the peripheries of said tumblers, means engageable with said lever to rock said lever against the opposition of said retaining means and in a direction to further separate said fence from said tumbler peripheries in which position said lever rocking means become effectively uncoupled from said lever and at least said retaining means rock said lever in an opposite direction to bring said fence into engagement with said gates provided that said gates are in alignment, and means to temporarily retain said lever in the position at which said fence engages said gates until the lock is completely operated after which said lever is movable again to said rest position.

12. In a combination lock having a tumbler assembly provided with gates, and a fence lever having a fence to engage the gates when the tumblers of said assembly are each in a predetermined position; a support retaining said lever in a rest position at which said fence is spaced from said tumblers so that during movement of said tumblers there is no contact between the tumblers and fence, means for moving said lever from said rest position in a direction which further spaces said fence from said tumblers and then releases said fence lever, and means effective upon release of said fence lever for returning said lever through said rest position to a position at which said fence engages said gates.

13. The subject matter of claim 12 wherein said lever returning means moves said lever to said rest position if said gates are not aligned with said fence when said fence has been returned through said rest position, and means to retain said fence engaged with said gates if said gates are aligned with said fence when said fence has been returned through said rest position.

14. The subject matter of claim 12 wherein said lever returning means include a magnet.

15. The subject matter of claim 12 wherein said lever returning means include a spring.

16. In a combination lock having an assembly of tum blers provided With gates, the improvement comprising a movable member Whose motion is constrained to apredetermined path,- a fence connected'with said member, said movable member having a rest position at which said fence is spaced from said tumblers, means for moving said member from said rest position to initiate a cycle of movement of said member where a cyc ic includes movement in a manner that the fence moves respectively toward and away from said tumblers; said member moving means effective to drive said member during only a 10 portion of said cycle and "oeing ineffective to drive said References Cited in the file of this patent UNITED STATES PATENTS 550,655 Stone Dec. 3, 1895 2,601,774 Behrens et a1. July 1, 1952 2,775,114 Lee Dec. 25, 1956 

2. A COMBINATION LOCK COMPRISING A TUMBLER ASSEMBLY PROVIDED WITH MEANS TO TURN THE TUMBLERS THEREOF, AND A FENCE LEVER HAVING A FENCE TO ENGAGE THE GATES OF THE TUMBLERS WHEN THE TUMBLERS ARE IN PREDETERMINED RELATIVE POSITION, MEANS TO RETAIN SAID LEVER IN A NORMAL POSITION AT WHICH SAID FENCE IS SPACED FROM THE EDGES OF SAID TUMBLERS, AND MEANS FOR ROCKING SAID LEVER IN A DIRECTION TO FIRST SPACE SAID FENCE FARTHER FROM SAID TUMBLERS AND THEN MOVE SAID LEVER TOWARD SAID TUMBLERS FOR SAID FENCE TO ENGAGE SAID GATES. 